Hi there, I need to isolate a protozoa species from sample collected from industrial area. I treated the samples with Gentamycin, Penecillin and Streptamycin to eliminate bacteria inside. What happen after this is the fungus and yeast and some bacteria can still be observed after the treatment. I treat the sample with 5% HCL overnight and wash it with saline. After the treatment, yeast still can be observed from the sample and the protozoa form cycts, which is quite difficult for me to differentiate them. After 1 day culture with media, yeast become more while protozoa become less when observing under the microscope. Anyone know any method to isolate the protozoa from the industrial sample?